Rekeyable axial pin tumbler lock

ABSTRACT

An axial pin tumbler lock is provided with means for rekeying the lock without disassembling the lock. Means are provided for removing an old master key from the lock at a rekeying position, and groove means are included which expose a locking pin for removal. A new pin of differing length can be inserted in the lock and the lock re-locked by a new master key. Service keys are also provided which cannot be used to rekey the lock.

United States Patent [1 1 Falk [H1 3,728,880 [451 Apr. 24,1973- REKEYABLE AXIAL PIN TUMBLER LOCK [75 Inventor: Sidney Falk, Chicago, Ill.

[ 73] Assignee: Fort Lock Corporation, Chicago, Ill.

[22] Filed: Feb. 10, 1972 [2]] Appl. No.1 225,164

[52] US. Cl "70/363, 70/382 [51 Int. Cl. ..E05b 27/08 [58] Field of Search ..70/363, 382-385 [5 6] References Cited UNITED STATES PATENTS 3,102,412 Christopher ..70/363 7/ l 966 Kerr ..70/363 1/1969 Monahan ..70/363 Primary Examiner-Rober L. Wolfe AtlorneyC. Frederick Leydig et al.

[ 5 7 ABSTRACT An axial pin tumbler lock is provided with means for rekeying the lock without disassembling the lock. Means are provided for removing an old master key from the look at a rekeying position, and groove means are included which expose a locking pin for removal. A new pin of differing length can be inserted in the lock and the lock re-locked by a new master key. Service keys are also provided which cannot be used to rekey the lock.

9 Claims, 9 Drawing Figures PATENTEUAPR 24 1915 I sum 2 OF 2 REKEYABLE AXIAL PIN TUMBLER LOCK DESCRIPTION OF THE INVENTION This invention relates generally to axial pin tumbler locks and more particularly concerns axial pin tumbler locks which may be easily rekeyed.

During recent years, axial pin tumbler locks have found increasing favor in applications requiring a rugged lock of high security. In these locks, locking pins are moved in an axial direction by a tubular key inserted into an annular keyway. The axial orientation of the pins, the annular keyway and other factors make such locks hard to pick or otherwise open by unauthorized means. U.S. Pats. Nos. 3,415,086 and 3,509,748 illustrate locks of this general type.

Increased flexibility of application for such locks can be provided by making the locks rekeyable. Such rekeyable locks may find wide applications in situations where it may be necessary to change, or rebuild, the locks at more than infrequent intervals. For example, a vending machine owner may find such a lock useful. After installing a lock embodying the present invention, the machine owner may retain possession of a master lock key and provide an employee with a service key. Using the service key, the employee can operate the lock any number of times to service the vending machine. If the service key is lost or if other factors require it, the old keys can be rendered ineffective by rekeying the lock. To accomplish this rekeying in accordance with the present invention, the master key need only be inserted in the lock, the lock opened, and a locking pin withdrawn from the lock. A new locking pin of differing length can then be inserted in the lock and a new master key used to position the new pin in the mechanism and to relock the lock. Thereafter, the old service key and old master key will be ineffective to operate the lock, while a new service key will operate the lock and the new master key will both operate the lock and permit withdrawal of the newly inserted tumbler pin.

All locks can, of course, be rekeyed by removing the mechanism from the lock body, disassembling the lock, and replacing the pin tumblers. However, this disassembly and reassembly procedure can be a time consuming, expensive, and sometimes delicate operation. By providing a rekeyable lock which need not be entirely disassembled to be rekeyed or to have the pin tumblers replaced, a lock of great versatility is provided.

It is therefore the principal object of the invention to provide a lock which may be rekeyed quickly and easily without disassembly of the entire lock.

It is a related object to provide a lock which may be operated using a service key and both operated and rekeyed using a separate master key.

A more specific object is to provide a lock wherein at least one locking pin can be quickly and easily changed, rendering old keys ineffective for operating the lock.

It is another object to provide a rekeyable lock which can be assembled primarily from parts used in similar but non-rekeyable locks thereby rendering the manufacture and maintenance of the rekeyable locks relatively simple and inexpensive.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which FIG. I is a general perspective view of a lock embodying the present invention;

FIG. 2 is a partial sectional view taken substantially in the plane of line 2-2 in FIG. 1, and showing interior parts of the lock;

FIG. 3 is an end view taken substantially in the plane of line 3-3 in FIG. I and showing the exterior appearance of the lock mechanism;

FIG. 4 is a sectional view taken substantially in the plane of line 2-2 in FIG. 1 and showing the position of the lock components when an operating tubular key is inserted therein;

FIG. 5 is a perspective view showing the details of a service key for use with the lock;

FIG. 6 is a perspective view showing the details of a master key for use with the lock;

FIG. 7 is a sectional view taken substantially in the plane of line 7-7 in FIG. 2 showing the lock interior in its locked condition;

FIG. 8 is a sectional view taken substantially in the plane of line 7-7 and FIG. 2 showing the position of the lock parts in a lock-operated position with a tumbler ready for extraction; and

FIG. 9 is a sectional view taken substantially in the plane of line 2-2 in FIG. 1 showing the lock with a locking drive pin removed and the lock ready for rekeying.

While the invention will be described in connection with a preferred embodiment, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention.

Turning to the figures, there is shown, in FIG. 1, a typical lock installation using the present invention, the lock installation here being in a pad lock 10. In its illustrated embodiment, a locking mechanism 11 for the pad lock 10 includes a casing 12 and a spindle 13 mounted for rotation within the casing 12. When the spindle I3 is rotated within the casing 12, shackle freeing mechanism not shown releases the shackle 14 of the pad lock 10 so that it may be partially pulled from the lock 10 in the usual manner. It will be understood that when the described lock mechanism is used in other applications, rotation of the spindle 13 within casing 12 can serve to free door latches or actuate other known securing mechanisms.

In the illustrated device, the lock 10 is secured against unauthorized operation by securing the spindle 13 against unauthorized rotation within the spindle 12. To this end, a number of tumbler pins 16 are carried in wells I7 arranged circumferentially about the axis of the lock (see FIG. 3). Each tumbler pin 16 is biased toward a mating driver pin 18 by springs 19 or other means conveniently carried within the well 17. Each I tumbler pin 16 and drive pin 18 meet at a pin interface 20. Ordinarily, when no key is inserted in the lock, the tumbler pins 16 are positioned as shown in FIG. 2 so as to bridge a radially oriented interface 22 between the casing 12 and the spindle 13. The tumbler pins 16, being located partially within the casing 12 and partially within the spindle l3, prevent the spindle from being rotated with respect to the casing 12.

To operate the lock, an appropriate service key 25 or master key 26, like those shown respectively in FIGS. 5 and 6, may be inserted into an operating position in an annular lock keyway 27. When the key is so inserted, small bites 28 formed upon the periphery of the key engage the ends of the drive pins 18. Further insertion of the key 25 fully into the lock forces the driver pins 18 and the mating tumbler pins 16 into the bores of the wells 17 against the action of the biasing springs 19.

The axial depth of the bites 28 and the lengths of the tumbler pins 18 are chosen so that the pin interfaces 20 will be aligned with the spindle-casing interface 22. When the pin interfaces 20 and spindle-casing interfaces 22 are aligned as shown in FIG. 4, no tumbler pin 16 or driver pin 18 bridges the casing-spindle interface 22, and the spindle 13 is free to be rotated within the casing 12 by rotative pressure applied to the inserted key 25 or 26. If, however, a key having a bite 28 of incorrect axial length is inserted into the lock, either the tumbler pin 16 or the driver pin 18 will be positioned so as to bridge the casing-spindle interface 22, thereby preventing spindle rotation and lock operation.

To orient the key 25 or 26 properly for insertion into the lock, each key is provided with a lug 31 or 32, and the keyway 27 is formed with a notch 33 ofa depth sufficient to accept the lug 31 or 32. When rotative pressure is applied to the key 25 or 26, a key spindle lug 34 engages a spindle notch 35 to assist in rotation of the spindle 13. When the spindle 13 is rotated and the lock is operated, the driver pins 18 carried in the spindle 13 are also rotatably displaced.

in accordance with the invention, the described lock is provided with mechanism permitting the lock to be rekeyed. In the illustrated embodiment, the rekeying mechanism includes a rounded groove 37 formed in the casing periphery of the annular keyway 27. To rekey the lock, the master key 26 is inserted into the lock and the lock is operated by rotating the master key about one-fourth turn, so as to rotate the spindle 13 from the position shown in FIG. 7 to the position shown in FIG. 8.

When so positioned, the master key 26 can be withdrawn from the lock, thereby exposing a driver pin 18 behind the rekeying groove 37. The exposed driver pins 18 can then be removed from the lock, as shown in FIG. 9. After the old driver pin 18 is removed, a new driver pin of differing length may be inserted into the lock through the rekeying groove 37, and a new master key having bites 28 of appropriate depth can be used to re-lock the lock. The lock is constructed so that no pin or a fixed dummy pin is exposed at the rekeying groove when the spindle is oriented in the normal operating position. This construction, of course, prevents loss of a pin when the lock is locked and no lug is inserted in the lock.

To properly orient the master key 26 and spindle 13 in the rekeying position, a second notch 36 is provided in the periphery of the keyway 27. This shallow notch 36 permits the relatively short lug 32 of the master key 26 to slide in and out of the key when the key is located in this rekeying position.

It will be noted that, by providing the relatively thin notch 36 and the mating thin lug 32 on the master key 26, the master key can be withdrawn only at a given rekeying position, and only a given driver pin can be exposed. Alternatively, no lug 32 need be provided on the master key 26. The lack of any lug will allow the master key 26 to be withdrawn from the lock at any angular position, thereby exposing any desired driver pin at the rekeying groove 37.

The service key 25 can be used to operate the lock, but will not permit the removal of a pin or the rekeying of the lock. To this end, the service key 25 is provided with a relatively thick lug 31. This lug 31 will, of course, fit through the operating notch 33, but is formed so as to be too large to allow its withdrawal through the rekeying notch 36, or at any other angular position of the key. Since the service key 25 can be withdrawn from the lock only at the locking and unlocking position, no pin will be exposed for removal through the rekeying groove 37.

I claim the following:

1. in a lock having a casing and a spindle rotatable within the casing, and meeting the casing at a spindlecasing interface, at least one pin well formed in the easing and spindle across the casing-spindle interface, a tumbler pin and a driver pin carried in the well and abutting at a pin interface, the pins being movable in the well by the insertion of a key in the lock to align the pin interface with the casing-spindle interface and permit lock operation, the improvement comprising means for rekeying the lock without removing the spindle from the casing, including groove means dispose in front face of the casing for exposing at least one pin for removal from a well and for permitting the replacement of that pin with a new pin of a different length, means for permitting the removal of the key from the lock where a pin is positioned for exposure at the groove means, and a new pin of a length differing from the removed pin for insertion in the exposed lock well, insertion of the new pin thereby requiring a new key for lock operation.

2. In an axial-pin tumbler lock having a casing including a plurality of pin wells oriented axially of the lock and located in a circle therein, a spindle rotatable within the casing and having a correspondingplurality of pin wells formed therein in a corresponding circle for alignment with the casingwells across a casing-spindle interface, a corresponding plurality of tumbler pins and driver pins carried in the wells and abutting at pin interfaces, a master key formed with a corresponding plurality of bites for engaging the driver pins and moving them a pre-determined distance in the wells as the key is inserted in the lock to align the pin interfaces with the casing-spindle interface and allow lock operation, and means for aligning the key with the lock in a lock-operating position, the improvement comprising means for rekeying the lock without removing the spindle from the casing, including means permitting the removal of a master key from the lock at a rekeying position, groove means dispose in the front face of the casing for exposing at least one pin for removal from a well, a new pin of a length differing in length from the old pin for insertion in the well vacated by the old pin, and a new master key formed for insertion into the lock at the rekeying position and provided with bites for engaging all the driver pins and moving them predetermined distances to align all the pin interfaces with the casing-spindle interface to allow lock operation by the new key.

3. A lock according to claim 2 wherein no pin is exposed for removal from the lock when the spindle and pins carried by the spindle are located at the lockoperating position.

4. A lock according to claim 2 including a service key formed for insertion into and removal from the lock only at the lock-operating position, thereby preventing the exposure of any pin at the rekeying groove when the service key is in the lock.

5. A lock according to claim 2 wherein the lock includes an old service key form operating the lock when the old pin is installed, and a new service key for operating the lock when the new pin is installed, the service lugs and lock being formed to prevent the removal of either service key from the lock at any but the lock operating position.

6. A lock according to claim 5 including a relatively deep notch and a relatively shallow notch formed upon a keyway periphery at relatively angularly displaced positions, and wherein the master and service keys are formed with lugs insertable into the deep notch for orienting the keys in lock-operating positions, and the master key is formed with a relatively shallow lug permitting the insertion and withdraw] of the lug and key in the lock and keyway at either the lock-operating or lock-rekeying positions.

7. A lock according to claim 6 wherein the service key is provided with a relatively thick lug which permits the insertion and withdrawl of the key in the lock at the lock-operating position but which prohibits the removal or insertion of the key at any other rotatably displaced position.

8. A lock according to claim 7 wherein all master keys for a given rekeyable lock are provided with a relatively thin lug for insertion and withdrawl at the lock operating and the lock-rekeying positions, and all service keys are provided with a relatively thick lug for insertion and withdrawl from the lock only at the lockoperating position.

9. In an axial pin tumbler lock having a spindle rotatably carried in a case and meeting at a spindle-casing interface and having at least one axially oriented well formed in the spindle and casing and intersecting the spindle-casing interface, a tumbler pin and a driver pin carried in the well and meeting at a pin interface, at least one pin bridging the casing-spindle interface to prevent unauthorized lock operation, the lock requiring a key shaped to move pins in the wells axially of the lock to locate the pin interfaces at the casing-spindle interface so as to permit spindle rotation and lock operation when the key is inserted in the lock, the improvement comprising means permitting the removal of a master key from the lock at a rekeying position, means dispose in the front face of the casing permitting the removal of at least one pin from a well when the key is removed from the lock at the rekeying position, a new pin of length differing from the old pin for insertion in the old pins place in the well, and a new key being required to move the pins a new distance in the well to locate the pin interface at the casing-spindle interface to permit lock operation. 

1. In a lock having a casing and a spindle rotatable within the casing, and meeting the casing at a spindle-casing interface, at least one pin well formed in the casing and spindle across the casing-spindle interface, a tumbler pin and a driver pin carried in the well and abutting at a pin interface, the pins being movable in the well by the insertion of a key in the Lock to align the pin interface with the casing-spindle interface and permit lock operation, the improvement comprising means for rekeying the lock without removing the spindle from the casing, including groove means dispose in the front face of the casing for exposing at least one pin for removal from a well and for permitting the replacement of that pin with a new pin of a different length, means for permitting the removal of the key from the lock where a pin is positioned for exposure at the groove means, and a new pin of a length differing from the removed pin for insertion in the exposed lock well, insertion of the new pin thereby requiring a new key for lock operation.
 2. In an axial-pin tumbler lock having a casing including a plurality of pin wells oriented axially of the lock and located in a circle therein, a spindle rotatable within the casing and having a corresponding plurality of pin wells formed therein in a corresponding circle for alignment with the casing wells across a casing-spindle interface, a corresponding plurality of tumbler pins and driver pins carried in the wells and abutting at pin interfaces, a master key formed with a corresponding plurality of bites for engaging the driver pins and moving them a pre-determined distance in the wells as the key is inserted in the lock to align the pin interfaces with the casing-spindle interface and allow lock operation, and means for aligning the key with the lock in a lock-operating position, the improvement comprising means for rekeying the lock without removing the spindle from the casing, including means permitting the removal of a master key from the lock at a rekeying position, groove means dispose in the front face of the casing for exposing at least one pin for removal from a well, a new pin of a length differing in length from the old pin for insertion in the well vacated by the old pin, and a new master key formed for insertion into the lock at the rekeying position and provided with bites for engaging all the driver pins and moving them predetermined distances to align all the pin interfaces with the casing-spindle interface to allow lock operation by the new key.
 3. A lock according to claim 2 wherein no pin is exposed for removal from the lock when the spindle and pins carried by the spindle are located at the lock-operating position.
 4. A lock according to claim 2 including a service key formed for insertion into and removal from the lock only at the lock-operating position, thereby preventing the exposure of any pin at the rekeying groove when the service key is in the lock.
 5. A lock according to claim 2 wherein the lock includes an old service key for operating the lock when the old pin is installed, and a new service key for operating the lock when the new pin is installed, the service lugs and lock being formed to prevent the removal of either service key from the lock at any but the lock operating position.
 6. A lock according to claim 5 including a relatively deep notch and a relatively shallow notch formed upon a keyway periphery at relatively angularly displaced positions, and wherein the master and service keys are formed with lugs insertable into the deep notch for orienting the keys in lock-operating positions, and the master key is formed with a relatively shallow lug permitting the insertion and withdrawl of the lug and key in the lock and keyway at either the lock-operating or lock-rekeying positions.
 7. A lock according to claim 6 wherein the service key is provided with a relatively thick lug which permits the insertion and withdrawl of the key in the lock at the lock-operating position but which prohibits the removal or insertion of the key at any other rotatably displaced position.
 8. A lock according to claim 7 wherein all master keys for a given rekeyable lock are provided with a relatively thin lug for insertion and withdrawl at the lock operating and the lock-rekeying positions, and all service keys are provided with a relatively thick lug for insertion and withdRawl from the lock only at the lock-operating position.
 9. In an axial pin tumbler lock having a spindle rotatably carried in a case and meeting at a spindle-casing interface and having at least one axially oriented well formed in the spindle and casing and intersecting the spindle-casing interface, a tumbler pin and a driver pin carried in the well and meeting at a pin interface, at least one pin bridging the casing-spindle interface to prevent unauthorized lock operation, the lock requiring a key shaped to move pins in the wells axially of the lock to locate the pin interfaces at the casing-spindle interface so as to permit spindle rotation and lock operation when the key is inserted in the lock, the improvement comprising means permitting the removal of a master key from the lock at a rekeying position, means dispose in the front face of the casing permitting the removal of at least one pin from a well when the key is removed from the lock at the rekeying position, a new pin of length differing from the old pin for insertion in the old pin''s place in the well, and a new key being required to move the pins a new distance in the well to locate the pin interface at the casing-spindle interface to permit lock operation. 